Abstract
We have investigated the feasibility of enhancing expression of an immunoglob-ulin-based vector in myeloma cells by coamplification with a mutant dihydrofo-late reductase (mDHFR) gene. Expression of the vector was monitored by the use of tissue plasminogen activator (t-PA) as a reporter gene. During progressive increases of methotrexate concentration in the culture media, the mDHFR gene and the linked t-PA gene amplified approximately 30-fold. A similar increase in mDHFR and t-PA mRNAs was observed. Production of t-PA protein increased in parallel with DNA copy number and RNA, reaching levels 30 to 40-fold higher than those prior to DNA amplification. The capability of amplifying copy number and expression of nonimmunoglobulin genes enhances the utility of this vector-host system for high level production of desired proteins for therapeutic and diagnostic applications.
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Hendricks, M., Luchette, C. & Banker, M. Enhanced Expression of an Immunoglobulin-Based Vector in Myeloma Cells Mediated by Coamplification with a Mutant Dihydrofolate Reductase Gene. Nat Biotechnol 7, 1271–1274 (1989). https://doi.org/10.1038/nbt1289-1271
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DOI: https://doi.org/10.1038/nbt1289-1271
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